In a telephone switching center, problems arise when relatively large echoes are received from one or more of the outgoing trunks. To address this problem, each of the outgoing trunks in a switching center has traditionally been assigned a dedicated echo cancellation unit to suppress any echoes received from the trunk. However, only a small percentage of the outgoing trunks in a switching center normally experience echo problems during normal system operation. Therefore, more echo cancellation functionality is being provided than is necessary to ensure quality communication in the network.
Therefore, there is a need for a method and apparatus for suppressing harmful echoes in a switching center that does not require dedicated echo cancellation functionality on each outgoing trunk.